• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.10 s.352
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• pp.46-54
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• 2006

In this paper, we propose a digital transceiver that can overcome the problems which current analog transceivers have. For the proposed transceiver, we assumed a frequency resource that consists of discrete and narrow channels. We also assumed that person-to-group, group-to-group, as well as person-to-person, voice and data communications with moderate security should be devisedand the data rate is 1 Mbps with simultaneous voice and data. Frequency hewing spread spectrum (FH-SS) and differential 8-PSK (D8PSK) were adopted for security reasons and bandwidth constraints, and for the reduction of implementation complexity, respectively. For the carrier and the symbol timing recovery, the structure of the preamble was proposed based on the IEEE 802.11 FHSS frame format to improve detection probability. The computer simulation results and power budget analysis implies that the proposed system can be usedin simple wireless communications in place of such as analog walkie-talkies.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.5
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• pp.332-346
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• 2003

In this paper, a system which can compress and reconstruct the digital image was implemented using 2 dimensional DWT(Discrete Wavelet Transform). The proposed system consists of the FPGA board tocompress the image and the application software(S/W) to reconstruct it. First the FPGA receives the image from AID converter and compresses the image using wavelet transform. The compressed data is transferred into the PC using the PCI interface. The compressed image is reconstructed by an application S/W inside the PC. The image compressor can compress about 60 fields per second, in which the image format was NTSC YCbCr(4:2:2) and the image size was 640${\times}$240 pixels per field. The designed hardware mapped into one FPGA occupying 11,120 LAB (Logic Array Block) and 27,456 ESB(Embedded System Block) in APEX20KC EP20K1000B652-7. It globally uses 33MHz clock and the memory control part uses 100MHz.

• KEPCO Journal on Electric Power and Energy
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• v.3 no.2
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• pp.89-97
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• 2017

The substation is a critical node in the power network where power is transformed in the power generation, transmission and distribution system. The IEC 61850 is a global standard which proposes efficient substation automation by defining interoperable communication and data modelling techniques. In order to achieve this level of interoperability and automation, the IEC 61850 (Part 6) defines System Configuration description Language (SCL). The SCL is an XML based file format for defining the abstract model of primary and secondary substation equipment, communications systems and also the relationship between them. It enables the interoperable exchange of data during substation engineering by standardizing the description of applications at different stages of the engineering process. To achieve the seamless interoperability, multi-vendor devices are required to adhere completely to the IEC 61850. This paper proposes an efficient algorithm required for verifying the interoperability of multi-vendor devices by checking the adherence of the SCL file to specifications of the standard. Our proposed SCL validation algorithm consists of schema validation and other functionalities including information model validation using UML data model, the Vendor Defined Extension model validation, the User Defined Rule validation and the IED Engineering Table (IET) consistency validation. It also integrates the standard UCAIUG (Utility Communication Architecture International Users Group) Procedure validation for quality assurance testing. Our proposed algorithm is not only flexible and efficient in terms of ensuring interoperable functionality of tested devices, it is also convenient for use by system integrators and test engineers.

• The KIPS Transactions:PartD
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• v.9D no.6
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• pp.1009-1016
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• 2002

We design and implement a new case-based recommender system using implicit rating information for a digital content site. Our system consists of the User Profile Generation module, the Similarity Evaluation and Recommendation module, and the Personalized Mailing module. In the User Profile Generation Module, we define intra-attribute and inter-attribute weight deriver from own's past interests of a user stored in the access logs to extract individual preferences for a content. A new similarity function is presented in the Similarity Evaluation and Recommendation Module to estimate similarities between new items set and the user profile. The Personalized Mailing Module sends individual recommended mails that are transformed into platform-independent XML document format to users. To verify the efficiency of our system, we have performed experimental comparisons between the proposed model and the collaborative filtering technique by mean absolute error (MAE) and receiver operating characteristic (ROC) values. The results show that the proposed model is more efficient than the traditional collaborative filtering technique.

• Journal of the Korean Society for information Management
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• v.18 no.4
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• pp.57-79
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• 2001

The study designs and implements a metadata management system for archival and manuscripts control. It has two purposes. First purpose is to organize the collection that the Institution of Korean Church History holds by using the proposed metadata format. Second purpose is to suggest the model and framework for managing the collection. The proposed metadata is designed based on ISAD(G), USMARC AMC, EAD and Ebind, By using the proposed metadata, the collection management system, which allows an integrated retrieval, is implemented. In order to evaluate the efficiency of the proposed system as well as to gain the basic data for the improvement of the proposed system, a questionnaire survey through e-mail is conducted. The evaluation results will be utilized for improving and upgrading the proposed system, and the phrased implementation of applying the system to digital libraries is suggested.

• Journal of the Korean Graphic Arts Communication Society
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• v.25 no.2
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• pp.29-44
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• 2007

The printing industry is getting more digitalized and integration. It has enabled the interactive information and networking from Pre-Press, Press, to the Post-Press. These are efficient management and the improved process and productivity are getting more important. Such trends improved in the functionality and automation. This paper tries to find out how technology for CIP3/4 -based process may be applied and resolved. Such subject includes the domestic and international cases regarding each manufacturer's CIP3/4 technology types. Another purpose is to emphasize on the needs to establish the environment. Under this environment, it is possible to integrate network in exchangeable form through JDF standard format after CIP3/4. Based on the data from this study, it is expected to collect further substantial data which is related to the domestic printing company's CIP 4 operation. It will be also possible to perform subsequent studies on the proper variables of the market segment. CIP4 stands for "International Cooperation for Integration of Prepress, Press and Post-press, it is an association of around forty international companies, mostly manufacturers of prepress, press and post-press, as well as suppliers and users. In this paper, we studied on the acting application of CIP4 work flow.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.5
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• pp.925-938
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• 2010

Depending on network conditions, a communication network could be overloaded when media are transmitted. Research has been carried out to lessen network overloading, such as by filtering, load distribution, frame dropping, and other methods. Among these methods, one of the most effective is frame dropping, which reduces specified video frames for bandwidth diminution. In frame dropping, B-frames are dropped and then I- and P-frames are dropped, based on the dependency among the frames. This paper proposes a scheme for protecting copyrights by encryption, when frame dropping is applied to reduce the bandwidth of media based on the MPEG-4 file format. We designed two kinds of frame dropping: the first stores and then sends the dropped files and the other drops frames in real time when transmitting. We designed three kinds of encryption methods using the DES algorithm to encrypt MPEG-4 data: macro block encryption in I-VOP, macro block and motion vector encryption in P-VOP, and macro block and motion vector encryption in I-, P-VOP. Based on these three methods, we implemented a digital rights management solution for MPEG-4 data streaming. We compared the results of dropping, encryption, decryption, and the quality of the video sequences to select an optimal method, and found that there was no noticeable difference between the video sequences recovered after frame dropping and the ones recovered without frame dropping. The best performance in the encryption and decryption of frames was obtained when we applied the macro block and motion vector encryption in I-, P-VOP.

• Journal of Radiation Protection and Research
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• v.43 no.2
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• pp.59-65
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• 2018

Background: We analyzed changes in the doses, structure volumes, and dose-volume histograms (DVHs) when data were transferred from one commercial treatment planning system (TPS) to another commercial TPS. Materials and Methods: A total of 22 volumetric modulated arc therapy (VMAT) plans for nasopharyngeal cancer were generated with the Eclipse system using 6-MV photon beams. The computed tomography (CT) images, dose distributions, and structure information, including the planning target volume (PTV) and organs at risk (OARs), were transferred from the Eclipse to the MRIdian system in digital imaging and communications in medicine (DICOM) format. Thereafter, DVHs of the OARs and PTVs were generated in the MRIdian system. The structure volumes, dose distributions, and DVHs were compared between the MRIdian and Eclipse systems. Results and Discussion: The dose differences between the two systems were negligible (average matching ratio for every voxel with a 0.1% dose difference criterion = $100.0{\pm}0.0%$). However, the structure volumes significantly differed between the MRIdian and Eclipse systems (volume differences of $743.21{\pm}461.91%$ for the optic chiasm and $8.98{\pm}1.98%$ for the PTV). Compared to the Eclipse system, the MRIdian system generally overestimated the structure volumes (all, p < 0.001). The DVHs that were plotted using the relative structure volumes exhibited small differences between the MRIdian and Eclipse systems. In contrast, the DVHs that were plotted using the absolute structure volumes showed large differences between the two TPSs. Conclusion: DVH interpretation between two TPSs should be performed using DVHs plotted with the absolute dose and absolute volume, rather than the relative values.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.6C
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• pp.512-519
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• 2008

The proof of a cellular phone used to a crime important data of a criminal investigation and legal judgment become. A lot of on a process use the file format that do not become that is kind of various cellular phones and model pipe, and collect criminal proof, and to analyze be difficult. Also, standardization is not made, and can be adopted on procedures from confiscation search processes regarding a cellular phone to integrity extractions of Forensic data in courts in the confiscation criminal investigation spots. Standardize confiscation search procedures of a cellular phone at these papers. Use a radio waves interception envelope and radio waves interception device for a movement which a security does integrity of criminal on-site cellular phone confiscation search data by standard procedures, and was devoted to. Analyze corroborative facts of a cellular phone seized, and verify integrity, and present problems regarding cellular phone confiscation search procedures and measures, and will contribute in development of Mobile Forensic through integrity damage experiment.

• Journal of Korean Society for Geospatial Information Science
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• v.14 no.1 s.35
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• pp.29-36
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• 2006

In the process of location selection, it is assumed that transformer substation socially recognized as a dangerous facility require especially more rigorous and resonable process. This paper implements suitability analysis for optimum location selection of transformer substation in southern Gyeonggi province using AHP(Analytic Hierarchy Process) and spatial analysis of GIS in terms of safety, national land use, economical efficiency and environment preservation. To do this, necessary data from 1/5,000 digital map are extracted a s raster format for suitability analysis and a field investigation also was done. In the procedure of site selection, three candidate zones with 1.5km radius were selected for the whole research area and then through field survey low transformer sites were selected from candidate zones. In the last the appropriateness of selected sites was evaluated. The results of the suitability analysis showed that the first candidate site satisfied the location condition best and other candidate sites generally showed good location condition.